Filtering fuel nozzle for pressure stoves and lanterns



C. BRAMMING Jan. 17, 1956 2,731,299 FILTERING FUEL. NOZZLE FOR PRESSURE STOVES AND LANTERNS Filed May 1, 1953 United States Patent FILTERIN G FUEL NOZZLE FOR PRESSURE STOVES AND LANTERNS Carl Brarnming, Nashville, Tenn., assignor to Aladdin Industries, Incorporated, Nashville, Tenn., a corporation of Illinois Application May 1, 1953, Serial No. 352,330 Claims. (Cl. 299-107) This invention relates to hydrocarbon burners such as stoves and lanterns, and is more particularly related to the provision of a fuel filtering device associated with the fuel discharge nozzle and adapted to filter fuel immediately prior to its passing through the very small orifice in the fuel discharge nozzle.

Hydrocarbon burners must be constructed so as to perform satisfactorily for extended periods of time utilizing commercially available hydrocarbon fuels such as kerosene or gasoline. In pressure type stoves and lanterns, the fuel discharge orifice thereof is of relatively small diameter, being in the order of six to ten one-thousandths of an inch. Orifices of this size clog very readily, and accordingly must be protected in order that they perform etficiently.

Commercially available hydrocarbon fuels contain impurities and insufficiently refined fractions of hydrocarbon bases in quantities sufficient to clog the small fuel discharge orifice in a very short time. Accordingly, a fine mesh screen filtering device is usually provided to protect the orifice from the larger pieces of dirt, rust, scale, and other foreign matters. In spite of the use of these filters, however, these orifices tend to clok too readily for efiicient operation.

Additional clogging agents in commercially available hydorcarbons are the heavier fractions of fuel which tend to form carbon deposits at or adjacent the fuel discharge orifice, particularly when they are supported by minute pieces of foreign matter such as dirt or rust. Since the fuel discharge orifice is immediately adjacent the flame, the fuel discharge nozzle becomes extremely hot, which adds to the speed with which the heavier fractions of hydrocarbon fuel build up the carbon deposit.

It is accordingly an object of this invention to provide a filter immediately adjacent the fuel discharge nozzle, the filter being specifically built to remove foreign matters which have an effective diameter of only a fraction of the diameter of the fuel discharge orifice.

A further object is to provide a filter which may be built in a very inexpensive manner and which is easy to assemble.

A still further object is to provide a filter which can be manufactured in the extremely small sizes required in this art.

Further objects and advantages of this invention will be apparent from a consideration of the accompanying drawings in which:

Fig. 1 is a view in section on the center line of a fuel discharge nozzle constructed and arranged in accordance with the invention.

Fig. 2 is a view in section on a larger scale of the sleeve in which the filtering action is accomplished, and

Fig. 3 is a view in section on the line 33 of Fig. 2.

It must be appreciated that the devices with which we are here concerned are very small in the usual stove or lantern. For instance, the fuel discharge nozzle illustrated in Fig. 1 is usually made in the order of threequarters of an inch to an inch in length, and slightly over one-eighth of an inch in outside diameter. The sleeve shown in Fig. 2 is usually less than half an inch long and its outside diameter barely exceeds one-eighth of an inch. The very small overall size of these parts makes the tolerances of the individual parts very critical and requires careful planning and execution in order to accomplish the desired results.

As shown in Fig. l, the fuel discharge nozzle 10 is attached to a fuel supply pipe 11 by some means such as the silver solder 12 which holds the pipe 11 in the socket 13 formed in the cap 14. The fuel supply pipe 11 has an internal diameter in the order of one-sixteenth inch which is continued in the tubular bore 15 of the cap 14. The cap 14 is completed with a counter-bore 16 which is internally threaded as at 17.

It will be appreciated that fuel enters the nozzle 10 through the fuel pipe 11 and that it is desired to discharge this fuel through the orifice 18 in the burner tip 19. The The outside diameter of the tip 19 is approximately oneeighth of in inch, and the flattened portions 25) and 21 provide means for gripping the tip with a wrench. The opposite end of the tip 19 is threaded as at 22 and contains a main bore 23 which is tapered at 24 into the orifice 18. It is preferred that the orifice 18 be coaxial with the bore 23 and that the orifice 18 be accurately reamed to a size approximating six to seven thousandths of an inch. That diameter is not determinative of the scope of the claims herein excepting insofar as it may be related to the width of the filtering channel.

The burner tip sleeve 25 is formed at its lower end with an internal thread 26 adapted to mate with the external thread 22 on the burner tip 19. The upper end of the tip 19, as shown in Fig. 1, need not extend the full length of the thread 26 in the assembled condition. The sleeve 25 is formed at its upper end with an external thread 27 adapted to be received in the internal thread 17 in the cap 14.

The filtering action takes place in the: upper half of the sleeve 25. There the filter chamber 28 contains the ball 29. Since tolerances and clearances are critical in the construction of this filtering device, it is suggested that the chamber 28 be reamed to .113 inch for use with a ball 29 which is a commercial tolerance ball seven sixty-fourths of an inch in diameter. The ball exceeds .109 inch. With the ball in position, the total clearance in diameter is less than of an inch, and when the ball is centered, the clearance on each side of the ball is less than of an inch.

To provide additional filtering action, and to maintain the ball 29 centered relative to the chamber 28, the bore 30 is provided at its upper end with a countersunk shoulder 31. The cylindrical chamber 30 is provided with a number of uniformly distributed grooves 32 separated by a series of lands 33. Both the lands and the grooves are of a smaller elfective diameter than the diameter of the chamber 28. For instance, the effective diameter between the grooves 32 should be in the order of .110 inch while the effective diameter between the lands 33 is .100 inch. This will operate to center the ball 29 relative to the chamber 28 and to the chamber 30.

I have chosen to use the ball 29 as constructed from stainless steel with commercial tolerances. In this size, the tolerances are small enough that the ball will perform the filtering operation in cooperation with the particular chambers described. Any impurities or foreign materials which enter the chamber 28 through the fuel pipe 11 are filtered out by the annular filtering area between the ball 29 and the chamber 23, and between the ball 29 and the lands 33 and the grooves 32. This annular filtering area is of relatively small radial extent, being between one-half thousandth of an inch and almost two thousandths of an inch, in radial distance, while being of considerable extent, relatively, in annular distance. Being of the small extent radially, the filtering area will remove all but the finest of impurities, while being of a considerable extent in annular, length, there is a large total filtering area, almost all of which must become clogged before the action of the burner is appreciably affected. 7 The filter and burner tip may be easily disassembled for cleaning. Additionally, with the parts threaded in the particular manner shown and because of the use of the ball 29, reassembly is simple, and it is impossible to reassemble the parts improperly, if they are all used.

Having described my invention, what I claim as new and desire to protect by Letters Patent is: e l. A fuel filtering burner nozzle, comprising body means having a discharge orifice therein of relatively small diameter and an inlet opening therein of relatively large diameter, means in said body means forming a passage interconnecting said discharge orifice and said inlet opening, said passage including a filtering chamber, a ball positioned in said chamber, said chamber and said ball defining filtering passage means therebetween of a size substantially less than the size of said discharge orifice so that particles in the fuel of a size sufficient to clog the orifice cannot pass said ball.

2. A fuel filtering burner nozzle, comprising body 'means having a discharge orifice therein of relatively small diameter and an inlet opening therein of relatively large diameter, passage means in said body meansinterconnecting said discharge orifice and said inlet opening, said passage means including a cylindrical chamber, a ball positioned in said chamber, means for retaining said ball in said chamber, said chamber having a diameter exceeding the diameter of said ball by an amount substantially less than the diameter of said discharge orifice so that particles in the fuel of a size sufficient to clog said orifice cannot pass said ball,

than the diameter of said discharge orifice so that particles in the fuel of a size sufiicient to clog said orifice cannot pass said ball.

4. A fuel filtering burner nozzle, comprising body means having a discharge orifice therein of relatively small diameter and an inlet opening therein of relatively large diameter, means in said body means defining a passage interconnecting said discharge orifice and said inlet opening, said passage including first and second coaxial interconnected bores, said first bore communicating at its one end with said orifice and opening at its opposite end into said second bore, said second bore having a diameter greater than the diameter of said first bore, means between said bores forming a seat facing toward said inlet opening, a ball in said second bore engageable with said seat, said seat having a plurality of generally longitudinal grooves formed therein to conduct fuel around said ball, said grooves being substantially smaller in dimension than said discharge orifice so that particles in the fuel of a size sufficient to clog said orifice cannot pass through said grooves.

v 5. A fuel filtering burner nozzle, comprising body means having a discharge orifice and an inlet opening therein, first and second coaxial interconnected bores in said body means, said bores being in direct communication at adjacent ends thereof and having their opposite ends communicating respectively with said orifice and said inlet opening, said second bore having a diameter greater than the diameter of said first bore, means between said bores forming a seat facing toward said inlet opening, a ball in said second bore engageable with said seat, said first bore having a plurality of longitudinal flutes formed therein of a size substantially less than the size of said orifice to conduct fuel through said seat while filtering out particles of a size sufficient to clog said orifice, said bore having a radius exceeding the radius of said ball by an amount less than the diameter of said orifice to filter out particles of a size sufficient to clog said orifice.

References Cited in the file of this patent UNITED STATES PATENTS 

